A communication system is a facility which facilitates communication between two or more entities such as communication devices, network entities and other nodes. A communication system may be provided by one or more interconnected networks and the elements thereof and a plurality of communication devices, for example user devices. One or more gateway nodes may be provided for interconnecting various networks. For example, a gateway node can be provided between an access network and other communication networks. The communication may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and so on.
A communication system typically operates in accordance with a standard and/or a set of specifications and protocols which set out what the various elements of the system are permitted to do and how that should be achieved. For example, it is typically defined if the user, or more precisely a user device, is provided with a circuit switched bearer or a packet switched bearer, or both. Also, the manner in which user communication devices can access a communication system is typically defined, as is the manner in which communications should be implemented between the user device and various elements of the communication system. The functions and responsibilities of various entities are also typically defined by communication protocols.
A user may communicate via a communication system and access various applications by means of an appropriate communication device. The user communication devices are often referred to as user equipment (UE). An appropriate access system allows the communication device to communicate via the communication system. An access to the communications system may be provided by means of a fixed line or wireless communication interface, or a combination of these. Examples of wireless systems include cellular networks, various wireless local area networks (WLANs), wireless personal area networks (WPANs), satellite based communication systems and various combinations of these.
In wireless systems a network entity such as a base station provides an access node for communication devices. Typically the operation of a base station node and other apparatus of an access system required for the communication is controlled by an appropriate control entity. The control entity can be interconnected with other control entities of the communication network.
It has been proposed that control functions that have been handled in conventional network by a centralised controller can also be handled in a distributed manner. This kind of distributed architecture is sometimes referred to as a “flat architecture”. A non-limiting example of the flat architectures is a concept known as the Evolved Universal Terrestrial Radio Access (E-UTRA), also known as the long term evolution (LTE). An Evolved Universal Terrestrial Radio Access Network (E-UTRAN) consists of E-UTRAN Node Bs (eNBs) which are configured to provide base station and control functionalities of the radio access network. The eNBs may provide E-UTRA features such as user plane radio link control/medium access control/physical layer protocol (RLC/MAC/PHY) and control plane radio resource control (RRC) protocol terminations towards the mobile devices. The eNBs interface to an E-UTRAN access gateway (aGW) via a so called S1 interface, and are inter-connected via a so called X2 interface.
The Long Term Evolution (LTE) can provide several means for Quality of Service (QoS) control and differentiation. For example, each evolved packet system (EPS) bearer may be associated with the following parameters:                QoS Class Identifier (QCI); A QCI is a scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc.), and that have been pre-configured by the operator owning the access node (e.g. eNodeB). On the radio interface and on S1 each PDU (e.g. RLC PDU or GTP-u PDU) is indirectly associated with one QCI via the bearer identifier carried in the PDU header.        Allocation and Retention Priority (ARP). The primary purpose of ARP is to decide whether a bearer establishment/modification request can be accepted or needs to be rejected in case of resource limitations (typically available radio capacity in case of GBR bearers). In addition, the ARP can be used (e.g. by the eNodeB) to decide which bearer(s) to drop during exceptional resource limitations (e.g. at handover). Once successfully established, a bearer's ARP shall not have any impact on the bearer level packet forwarding treatment (e.g. scheduling and rate control). Such packet forwarding treatment should be solely determined by the other bearer level QoS parameters: QCI, GBR, MBR, and AMBR.        
Each GBR bearer may additionally be associated with the following bearer level QoS parameters:                Guaranteed Bit Rate (GBR); The GBR denotes the bit rate that can be expected to be provided by a GBR bearer.        Maximum Bit Rate (MBR); The MBR limits the bit rate that can be expected to be provided by a GBR bearer (e.g. excess traffic may get discarded by a rate shaping function). The MBR may be greater than or equal to GBR for a particular GBR bearer.        
Furthermore, each PDN connection (i.e. IP address) may be associated with the following IP-CAN session level QoS parameter:                Aggregate Maximum Bit Rate (AMBR); Multiple EPS bearers of the same PDN connection can share the same AMBR. That is, each of those EPS bearers could potentially utilize the entire AMBR, e.g. when the other EPS bearers do not carry any traffic. The AMBR limits the aggregate bit rate that can be expected to be provided by the EPS bearers sharing the AMBR (e.g. excess traffic may get discarded by a rate shaping function). AMBR applies to all Non-GBR bearers belonging to the same PDN connection. GBR bearers are outside the scope of AMBR.        
The GBR and MBR denote bit rates of traffic per bearer while AMBR denotes a bit rate of traffic per group of bearers. Each of those three bearer level QoS parameters has an uplink and a downlink component.
On top of the above mentioned QoS attributes in 3GPP also a prioritized bit rate (PBR) in the uplink is specified. PBR denotes the minimum bit rate for a bearer, such that the UE upon receiving an allocation for data transmission does the following:                Serve the bearers with their PBR in priority order;        If there is excess capacity left in the allocation, fill the excess capacity with traffic beyond the PBR but below the MBR per bearer in priority order.        
One ‘EPS subscribed QoS profile’ is defined for each APN permitted for the subscriber. It contains the bearer level QoS parameter values for that APN's default bearer (QCI and ARP) and that APN's AMBR.
In the eNB packet scheduling and admission control traffic is treated according to their QoS parameters in order to optimise the cell throughput and user satisfaction.
Existing systems describe how service differentiation may be implemented to ensure that services such as voice are prioritised over browsing. For example, US 2007/0002750 describes a system for scheduling packets in a wireless communication system where there are real-time users and non-real-time users.
There is a desire for both user differentiation and service differentiation so that operators may offer different levels of subscriptions.
It is an aim of the embodiments to provide a system which can allocate resources based upon priorities for services at different user levels, or at least provide a useful alternative.